1. Field of the Invention
The present invention relates to a method for providing a call processing service in a mobile communication network, and more particularly to a method for providing a call processing service in which a user can transmit his/her message to another party even when a traffic channel cannot be allocated due to traffic congestion.
2. Description of the Related Art
Generally, call traffic tends to increase sharply on a special day such as Christmas day or other special occasions. When a user of a mobile terminal is in a place where people gather on such a special day, he/she may have problems making or receiving a call. Namely, traffic in the mobile communication network enters such a congested state that it exceeds a traffic channel accommodation capacity of the network or system, thereby making it impossible for the system to allocate further traffic resources to a desired call. At this time, the wait time is excessive until available resources can be again provided, so the system releases the attempted call.
In such a case, a calling subscriber may be seriously inconvenienced since he/she is not aware of the reason why his/her call continuously fails to be connected. The subscriber may be more inconvenienced in cases that he/she must urgently communicate with the other party.
Recently, a technique has been developed which provides an announcement message to a subscriber in a wired network when a trunk line is in a congestion state. This technique is disclosed in Korean Patent Application No. 1999-59408, entitled “Apparatus For Sending Out Announcement Message In Case That V5.2 Interface Trunk Line Is In Congestion State”. V5.2 interface is one of standards for terminal device connection in case that data transmission is accomplished using an existing telephone network, which is well known. As disclosed in this application, the announcement message is provided using pre-allocated resources such as a dedicated channel for traffic. However, the use of the pre-allocated resources is very inefficient in radio environments. Since the above technique merely provides the announcement message, it cannot resolve a user's inconvenience when he/she has to communicate with others urgently.